Two-component polyurea coating compositions containing a polyisocyanate in combination with a polyaspartic ester component are known. They are suitable for the formation of coatings and can be adjusted to produce coatings that are hard, elastic, abrasion resistant, solvent resistant, and especially weather resistant.
U.S. Pat. No. 5,126,170 discloses a process for making polyurethane coatings in which an isocyanate-reactive component b) includes a polyaspartic ester mixture made from an optionally-substituted maleic or fumaric acid ester and a primary amine. U.S. Pat. No. 6,458,293 discloses a method for making an asymmetric polyaspartic ester mixture by sequentially (a) forming an ester mixture containing a dimethyl-substituted first ester component and a second ester component substituted with an alkyl group having at least two carbon atoms and (b) reacting the ester component with an amine component, such that the equivalent number ratio of the first ester component and the second ester component is sufficient to prevent the formation of a reaction-stopping crude mixture containing dimethyl fumarate crystals. US Patent Application Publication No. 2005/0075477 describes a process for preparing aspartates.